package string;


public class StringBuilderDemo {
    public static void main(String[] args) {
        String str = "好好学习Java";
        StringBuilder builder = new StringBuilder(str);
         //append():追加内容---在末尾增加
        builder.append(",为了找个好工作");
        System.out.println(builder);

        //replace():替换部分内容（含头不含尾）
        builder.replace(9,16,"就是为了改变世界");
        System.out.println(builder);

        //delete():删除部分内容
        builder.delete(0,8);
        System.out.println(builder); //,就是为了改变世界

        //insert():插入内容
        builder.insert(0,"或者");
        System.out.println(builder);

    }
    /*
    public static void main(String[] args) {
        StringBuilder builder1 = new StringBuilder(); //空字符串
        StringBuilder builder2 = new StringBuilder("abc"); //abc串

        String str = "abc";
        StringBuilder builder3 = new StringBuilder(str);
        String str2 = builder3.toString();

        */

}
